1997

Several spots of significant high flash density have been discovered in Austria. Most of these spots are associated with different types of radio towers on top of mountains. In this paper the triggering effect of tall structures is confirmed.

As an example we have analyzed the data from a lightning location system for one of these spots in more detail. 81 flashes have been detected during a period of two years at a distance of less than 1 km from a radio tower. Most of these flashes are assumed to be direct strikes to the tower. In average their peak amplitudes and their number of subsequent strokes are higher compared to flashes to ground in the vicinity of the tower.

At least seven visitors of an ice cave in the Austrian mountains have been injured inside the cave by a lightning strike. The accident was associated with a local electrical discharge over a distance of about one meter from the cave surface to the left shoulder of one of the victims. The victims location was covered by 300 m to 400 m of rock up to the ground striking point at the top of the mountain.